Ignition plug



H.. J. LINSE IGNITION PLUG May 21, 1929,

Filed Oct. 19, 1927 i ima dv figs Fig.4 F695,.

INVENTOR H m g 1 7 7458 ATTORN H ll atented Me er, ieea rren sr res HRBRY ll. LINSE, 0]!" 020m PARK, NEW YORK.

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Application filed October 19, 192i. Serial No. 227,094.

This invention relates to electric ignition plugs for use in internal combustion engines.

for igniting the fuel charge, and it is the object of the invention to provide an ignition plug which is adapted to be utilized as a means for observing the combustion of the fuel in the combustion chamber of an on g The ineficiency in operation of internal I10 combustion engines is well lrnown, which inelliciency in operation may be the result of one or more of many causes which are not apparent from an observation of the running of the engines such as an improper fuel mixture, improper design of the fuel intake manitolddrawing aninsutficient or improperly mixed fuel charge to certain 01 the cylinders in multiple cylinder engines, restricted exhaust ports and passages through the manifold leading from said ports, poor and def c ive ignition, or an unequal compression of the fuel charge. The corrections made for these faults are usually haphazard since the means are not available to the operator for determiningwhich one or more oi? the numerous causes is lowering the running eiiiciency of the engines, or whether the engine is operating under maximum etficiency. However, such causes afiecting the running efficiency of the engine could be readily ascertained were it possible to observe the combustion of the fuel. lt is the object of the present invention to provide an improved constructed and arranged ignition "plug torinternal combustion engines whereby the combustion of the fuel in the combustion chamber of the engine can be readily observed through the plug and the causes contributing to the inetficient running of the engine ascertained.

@ther objects and advantages will herematter appear among which isthe constrncit tion and arrangement of the insulator body and center electrode to compensate for thermal expansion and contraction of the parts.

In carrying out the invention 1 provide the usual shell electrode adapted for the mounting of the plug in an opening leading to the combustion chamber of an engine,- with a center electrode carrying insulator body or core oftransparent material, such as glass, mounted in the shell electrode with a portion thereof extended from the shell electrode and exterior otathe engine cylinder arranged with a prismatic surface or surfaces whereb the 'li ht in s enerated 3 e Y a:

- through the transparent insulator by-the combustion of the fuel which are transm1ttcd and directed longitudinally deflected laterally through the side wall of said body and readily'obscrvablc, the bore through the insulator body in which the center electrode is carried being preferably arranged with a reflective surface, although this is not absolutely essential, whereby the deflection of the light rays laterally through the side walls of the insulator body is great ly augmented. lo the drawing accompanying and formmg a part of this application, Figure l is an elevational view of an ignition plug and showing an embodiment of the present invention.

l igure 2 is a longitudinal sectional view of the spark plug shown in Figure l, and Figures 3 to 7, inclusive, are elevational views of a series of insulator bodies arranged with diflerent prismatic surface formations to carry out the invention.

and extending in a direction toward the interior of the threaded portion. lhe shell 15 arranged with an internal annular enlargement forming-a shoulder 11 for the seating of an insulator body or core 12 of transparent material, preferably of glass, engaged in the shell electrode; lln intermediate portion of the insulator body is arranged with an annular enlargement or flange 13, the lower surface of which is adapted to abut the seat 11 and the upper surface engaged by a sleeve or nut l l threaded into the end of the bore of the shell 8 to secure said insulator body in the shell with an end portion thereof extending beyond the one one terminating within the shell. The size of the insulator body relative to the shell is such as to compensate for the thermal expansionand contraction of the metal of the I shell and of the insulator body'to prevent vent loss of compression in the engine gas lrets 15 of the usual typefare interposed bebody are of the shell and the opposite end i ill) tween the flange 13 of the insulatoi' body and the seatll and said flange and the securing nut' 14.

An electrode in the form of a rod 16 is carried in a bore 23 centrally of the insulator body 12, the bore'being of greater diameter than the rod to compensate for expansion and contraction and prevent destruction of I the insulator body. 'lhe'one end of the; rod

extends beyond the shell adjacent the spark-- ing terminal 10. :The opposite end thereof is threaded and extends beyond the insulator or shoulder 18 for engagement with a shoulder formed by a recess 19 in the inner end of the insulator body with a washer 20 between the same, said shoulder on the rod being firmly drawn up against the shoulder formed by the recess to seal the end of the bore in the insulator body by a nut 21 en'- gaged on the threaded end of the rod below the binding nut 17. The rod electrode during the combustion of the, fuel in the combustion chamber of the engine becomes heated ,to a very high temperature and to dissipatethis heat and prevent injury to the insulator the rod is of greater diameter above the shoulder 17 than below the same, or that portion exposed directlyto the heat of combustion, as shown in Figure 2.

'lo deflect and diverge the light rays of combustion directed longitudinally through the insulator core laterally through the side of the insulator the outer surface of the in sulator body is formed as a refractive or prismatic surface or surfaces 22- These surfaces may be formed by cutting or molding the same in the surface of the insulator body and may be of variable formations, as shown in Figures 3 to 7 inclusive. These refractive or prismatic surfaces may be variously formed and disposed in anydesired manner about theinsulator body and of any p'redetermined angle. In Figures 1 to 3 the are circularly disposed around and exten ed radially of the insulator ody. In'Fig+ ure 4'they are in the form' o h continuous splral- In Figure 5 they are in the form of pyramids produced by a pair of spirals one evolved in clockwise direction-and'the other e in anti-celockwise direction and the two interr seating ach other. In Figure 6 theyare'of q diamond shape depressed into the surfaceof the insulator-body, and in Figure 7 they are circumferentially disposed around and extend longitudinally of the insulator body.

All of the above designs of refractive surfaces will prove effective in deflecting and diverging the light rays of combustion in a direction laterally of the insulator body.

rays the surfape of the bore 23 of the insulator body is arranged with a reflector or mirror surface to reflect the light rays from the center of the insulator body to the outer prismatic surfac'es. 1

It will be seenthat the light rays passup through the transparent body of the insulator and. are partially reflected and partially refracted topass laterally away from the insulator. v claim: 7 V 1. In an ignition plug a shell electrode adapted to be releasably mounted in the cylinder of an internal combustion engine, and a center electrode carrying insulator body of transparent material mounted in the shell and arranged with a refractive surface to deflect the light rays generated by the combustion of fuel in the engine cylinder laterally through the insulator body for visual observation.

2. In an'ignition plug, a shell electrode adapted to be releasably mounted in the cylinder of an internal combustion engine, a transparent insulator body carriedby the shell. having an extended portion arranged Having thus described my invention I fleeting surface, and a rod electrode mounted in the bore of the insulator bo'dy.

. 3. In an 1gn1t1on plug, a shell electrode adapted to be releasably mounted in, the cylinder of an internal combustion engine, a transparent insulator body mounted in the shell with a portion extending beyond one end of the shell arranged with prismatic surfaces to deflect the light rays generated 7 by the combustion of fuel in the engine cylinder and transmitted longitu inally through the insulator body laterally or observation through the side of said body, a .bore extending longitudinally of t e insulator, a coating of a reflective material on the wall of the bore, and a rod electrode mounted in and sealin said bore.

releasably mounted in the cylinder. of an internal combustion engine,

and i 4. In an i ition' p ug, a shell electrode adapted to a transparent insulator body having a'bore therethrough carried by the'shell having a portion extending. beyond one end of the shell and the outer. surface of said extended portion arranged with r-isms, a coating of reflective material on t e wall ofthe bore and a rod electrode carried in the bore, of said insulator-body.

,5. A transparent insulator body for electric ignition plugs having a bore therethrough and arranged with rismatic surfaces to reflect light rays de ected longitlb dinally through the body laterally ther f;

6. A transparent insulator body for electric ignition plugs as claimed claim 5,"

wherein the prismatic surfaces are arranged in the form of spirals evolved in opposite directions about the insulator body and intersecting each other.

1O. A transparent insulator bodyfor electric ignition plug as claimed in claim 5, wherein the prismatic surfaces are of diamond shape disposed circumferentially and longitudinally of the insulator body.

Signed at the city of New York, in the county of New York, and State of New York, this 10th day of October,.1927.

HARRY J. LINSE. 

